Fix bridge_with_irc

[rht]

This fixes #106.
Can be tested with

./irc-mirror.py --irc-server=irc.freenode.net --channel='#python-mypy' \
--nick-prefix='irc_mirror' \
--site="https://chat.zulip.org" --stream='test here' --topic='IRC' \
--user=<bot-email> --api-key=<bot-api-key>

Note the --stream arg is added here.

[zulipbot]

Hello @rht, it seems like you have referenced #106 in your pull request description, but you have not referenced them in your commit message description(s). When you reference an issue in a commit message, it automatically closes the corresponding issue when the commit is merged.

Please run git commit --amend in your command line client to amend your commit message description with Fixes #106..

An example of a correctly-formatted commit:

commit fabd5e450374c8dde65ec35f02140383940fe146
Author: zulipbot
Date:   Sat Mar 18 13:42:40 2017 -0700

    pull requests: Check PR commits reference when issue is referenced.

    Fixes #51.

Thank you for your contributions to Zulip!

[rht]

A test bridge between #python-mypy on irc.freenode.net and https://chat.zulip.org/#narrow/stream/7-test-here/topic/IRC has been made.

[rht]

One more test bridge with #git on https://chat.zulip.org/#narrow/stream/161-IRC/topic/IRC https://chat.zulip.org/#narrow/stream/161-IRC/topic/.23git (specifying topic name will be added later after this is merged added anyway).

[timabbott]

topic comparisons in Zulip should be case-insensitive, can you fix this comparison?

[rht]

Fixed via casefold() method, which handles unicode chars additionally instead of just lower().

[rht]

In zulip/zulip:

zerver/lib/topic.py
156:        canonical_name = topic_name.lower()

This should have been casefold() as well.

[timabbott]

I merged most of this, and posted a comment (which impacts the last few commits in a small way).

[timabbott]

Looks great, merged, thanks @rht!